The Healthy Nordic Diet and Mediterranean Diet and Incidence of Disability 10 Years Later in Home-Dwelling Old Adults.

Background/objective: Diet has a major impact on a person's health. However, limited information exists on the long-term role of the whole diet on disability. We investigated the association of the healthy Nordic diet and the Mediterranean diet with incident disability 10 years later.

Design: Longitudinal, with a follow-up of 10 years.

Settings/participants: A total of 962 home-dwelling men and women from the Helsinki Birth Cohort Study, mean age 61.6 years, who were free of disability at baseline.

Measurements: At baseline, 2001-2004, the Nordic diet score (NDS) and modified Mediterranean diet score (mMDS) were calculated using a validated 128-item food-frequency questionnaire. Higher scores indicated better adherence to the diet. Participants' incident disability was assessed during 2011-2013 by a self-reported questionnaire and was based on mobility limitations and difficulties to perform self-care activities. Analyses were performed using logistic regression and adjusted for potential confounding factors.

Results: In total, 94 participants (9.8%) developed mobility limitations and 45 participants (4.7%) developed difficulties in self-care activities during 10 year follow-up. The likelihood of having mobility limitations (odds ratio (OR) 0.42, 95% confidence interval (CI) 0.22-0.80) and difficulties in self-care activities (OR 0.38, 95% CI 0.15-0.94) were lower among those in the highest NDS tertile than among those in the lowest NDS tertile. Greater mMDS was associated with a lower disability incidence; however, the association was not statistically significant.

Conclusions/implications: Adherence to the healthy Nordic diet predicts 10-year incidence of mobility limitations and difficulties to perform self-care activities in old age and may thus be protective against disability in Nordic population.